Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

Pull perf fixes from Ingo Molnar:
 "Two kernel side fixes:

   - an Intel uncore PMU driver potential crash fix
   - a kprobes/perf-call-graph interaction fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU
  kprobes/x86: Fix page-fault handling logic

diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c
index 4b9a9e9..7c87424 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c
@@ -535,6 +535,7 @@ static int rapl_cpu_prepare(int cpu)
        struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu);
        int phys_id = topology_physical_package_id(cpu);
        u64 ms;
+       u64 msr_rapl_power_unit_bits;
 
        if (pmu)
                return 0;
@@ -542,6 +543,9 @@ static int rapl_cpu_prepare(int cpu)
        if (phys_id < 0)
                return -1;
 
+       if (!rdmsrl_safe(MSR_RAPL_POWER_UNIT, &msr_rapl_power_unit_bits))
+               return -1;
+
        pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu));
        if (!pmu)
                return -1;
@@ -555,8 +559,7 @@ static int rapl_cpu_prepare(int cpu)
         *
         * we cache in local PMU instance
         */
-       rdmsrl(MSR_RAPL_POWER_UNIT, pmu->hw_unit);
-       pmu->hw_unit = (pmu->hw_unit >> 8) & 0x1FULL;
+       pmu->hw_unit = (msr_rapl_power_unit_bits >> 8) & 0x1FULL;
        pmu->pmu = &rapl_pmu_class;
 
        /*
@@ -677,7 +680,9 @@ static int __init rapl_pmu_init(void)
        cpu_notifier_register_begin();
 
        for_each_online_cpu(cpu) {
-               rapl_cpu_prepare(cpu);
+               ret = rapl_cpu_prepare(cpu);
+               if (ret)
+                       goto out;
                rapl_cpu_init(cpu);
        }
 
@@ -700,6 +705,7 @@ static int __init rapl_pmu_init(void)
                hweight32(rapl_cntr_mask),
                ktime_to_ms(pmu->timer_interval));
 
+out:
        cpu_notifier_register_done();
 
        return 0;

diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 79a3f96..61b17dc 100644 (file)
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -897,9 +897,10 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
        struct kprobe *cur = kprobe_running();
        struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
 
-       switch (kcb->kprobe_status) {
-       case KPROBE_HIT_SS:
-       case KPROBE_REENTER:
+       if (unlikely(regs->ip == (unsigned long)cur->ainsn.insn)) {
+               /* This must happen on single-stepping */
+               WARN_ON(kcb->kprobe_status != KPROBE_HIT_SS &&
+                       kcb->kprobe_status != KPROBE_REENTER);
                /*
                 * We are here because the instruction being single
                 * stepped caused a page fault. We reset the current
@@ -914,9 +915,8 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
                else
                        reset_current_kprobe();
                preempt_enable_no_resched();
-               break;
-       case KPROBE_HIT_ACTIVE:
-       case KPROBE_HIT_SSDONE:
+       } else if (kcb->kprobe_status == KPROBE_HIT_ACTIVE ||
+                  kcb->kprobe_status == KPROBE_HIT_SSDONE) {
                /*
                 * We increment the nmissed count for accounting,
                 * we can also use npre/npostfault count for accounting
@@ -945,10 +945,8 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
                 * fixup routine could not handle it,
                 * Let do_page_fault() fix it.
                 */
-               break;
-       default:
-               break;
        }
+
        return 0;
 }